The transmission of digital data through channels, such as recording devices and data links, is known in the art. If errors are introduced in the data at any time during transmission through the channels, the received data is corrupted.
As is known in the art, the corrupt data is either no longer useful, such as is the case for corrupted bank account data, or is useful but with a significant decrease in the quality of the data, such as is the case for documents or images typically received by a facsimile machines.
Two well-known techniques are utilized to overcome the problem of introduction of errors in received data. They are error correction techniques and error detection techniques combined with data packetization.
In error correction techniques, redundant bits are added to the original data stream before transmission. If errors are introduced to the data, the error correction technique utilizes the redundant bits as well as the original data to correct the error. The quality of the correction depends on the type of error correcting algorithm as well as the number of redundant bits added.
In error detection techniques, the data is partitioned into packets to which are added redundant bits. The redundant bit is used to detect if errors have been added to the data in the packet. If an error is detected, the packet is retransmitted.
Both the error detection and the error correction techniques require the addition of redundant bits to the data to be transmitted. Recovery from errors is either by retransmission of the data with the errors or through utilization of data in the added redundant bits. It will be appreciated that addition of the redundant bits adds to the amount of data to be transmitted.